Microsoft .NET Framework 3.5 Microsoft .NET Framework 4.5.2 Microsoft .NET Framework 4.6 Microsoft .NET Framework 4.6.1 Microsoft .NET Framework 4.6.2 Microsoft .NET Framework 4.7 Microsoft .NET Framework 4.7.1 Microsoft .NET Framework 4.7.2 Microsoft .NET Framework 4.8
A remote code execution vulnerability exists in .NET software when the software fails to check the source markup of a file. An Authentication Bypass vulnerability exists in WCF and WIF, allowing signing of SAML tokens with arbitrary symmetric keys. This vulnerability allows an attacker to impersonate another user. The vulnerability exists in WCF, WIF 3.5 and above in .NET Framework, WIF 1.0 component in Windows, WIF Nuget package, and WIF implementation in Sharepoint. An information disclosure vulnerability exists when Exchange and Azure Active Directory allow creation of entities with Display Names having non-printable characters.
To learn more about the vulnerabilities, go to the following Common Vulnerabilities and Exposures (CVE).
As a reminder to advanced IT administrators, updates to .NET Framework 3.5 for Windows 8.1 and Windows Server 2012 R2 should only be applied on systems where .NET Framework 3.5 is present and enabled. Customers who attempt to pre-install updates to .NET Framework 3.5 to offline images that do not contain the .NET Framework 3.5 product enabled will expose these systems to failures to enable .NET Framework 3.5 after the systems are online. For more extensive information about deploying .NET Framework 3.5, see Microsoft .NET Framework 3.5 Deployment Considerations.
All updates for Windows 8.1, Windows RT 8.1, and Windows Server 2012 R2 require that update KB 2919355 is installed. We recommend that you install update KB 2919355 on your Windows 8.1-based, Windows RT 8.1-based, or Windows Server 2012 R2-based computer so that you receive updates in the future.
If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Add language packs to Windows.
Additional information about this update
The following articles contain additional information about this update as it relates to individual product versions.
4506977 Description of the Security Only Update for .NET Framework 3.5 for Windows 8.1 and Server 2012 R2 (KB4506977)
4506964 Description of the Security Only Update for .NET Framework 4.5.2 for Windows 8.1 and Server 2012 R2 (KB4506964)
4506962 Description of the Security Only Update for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2 for Windows 8.1 and Server 2012 R2 (KB4506962)
4506955 Description of the Security Only Update for .NET Framework 4.8 for Windows 8.1 and Server 2012 R2 (KB4506955)